You can find a lot of information on handlaying switches but this may be the first on "un-handlaying" switches.
I handlaid my last layout, moved, and plan to handlay the reincarnation of the layout in its new home. The new room is a bit larger and allows for some improvements in the track plan over the previous layout, so that means that a lot of the old layout will end up getting replaced. Pretty much only the Wilmington 6th St Yard will be reused as is. That leaves a whole lot of plywood that won't live in the new layout. But on that plywood are a lot of handlaid switches that can be reused. I built my switches based on templates made from prototype switch drawings (the 1922 P&R MofW rule book has plans for switches down to #3, yes three.) So most switches are built to consistent dimensions. I can unspike the rails of a switch from its existing location, lay new ties in a new location and relay the rails in the new location.
In order to keep the switch in tact as much as possible, I needed something keep the rails in gauge. The person who taught this technique to me at the Schuylkill Valley Model Railroad Club 40 years ago used tin strips that were used as bus bars in some industrial application. I have compromised by using sheet brass. I bought a sheet of 0.010 brass and then cut off narrow strips about 3/16" wide.
The width isn't magic, wider and it tends to block access to spikes and narrower it is less rigid. Also the thickness isn't horribly critical, but thinner brass tends to be a bit flimsy. I use regular scissors to cut the strips. they will require straightening, which can be done by rubbing a hard block or rod on the back or by hand straightening. (watch out for sharp edges). I hold the straightened strip in a pair of pliers and tin it by smearing on a bit of rosin flux and then coating the brass with solder. After doing one side, I flip the piece over and repeat on the other side.That strip is cut to length as needed to bridge across the switch.
Next comes planning where to cut the switch loose from the rest of the track. If there are rail joiners near the switch I make the break there. The vast majority of my switches have insulated frogs so there are natural breaks at the insulating gaps. As a last resort I will cut the rails a couple inches out from the switch. I generally like at least 4 strips across the switch. One on the single track before the points, two on the frog (one on each end) and one on the closure rails toward the frog. After locating where the strips will go, I remove spikes under the strip location. This is where it gets tricky. You have to leave enough spikes to hold the switch in shape, but remove the spikes under where the strips will go. The extra spikes are removed, I use an old pair of rail nippers (actually Radio Shack "flush cutting pliers", same difference).
I put a bit of rosin flux on the top of the rails where the strip will go, then using a hot iron that has some solder on it, tin the top of the rails. You want just enough that you can see a "silver" mark, but not a blob and you certainly don't want it down into the web.
Cut the tinned strip to go across all the rails at each location. You will want a bit of overhang (1/8 to 1/4") on both sides. Get a paper towel and rip it into quarters or so, then wet it. Place the strip across the rails and, using your biggest possible soldering iron, put the hot iron on top of the strip and solder it to the rail. It helps to use a pair of pliers or metal tool to hold the strip. Do not use your fingers (unless you are a robot and have metal fingers). When you have the solder melted, put the wadded up wet paper towel on the solder joint to solidify it and cool it quickly. When you move to the next rail use the wad of wet towel to cool the previous joint so it doesn't come loose. Repeat for each rail and each strip.
When all the strips are soldered securely, finish unspiking the switch. The quick and dirty way to do this is to remove just the spikes on one side of all rails. If there are electrical leads soldered to the rails those can be cut, unsoldered or carefully threaded back up through the holes from under the benchwork, when the switch is lifted. If there are connections to linkages for throwing the switch they will have to be disconnected. When all the leads and linkages are dealt with, "slide" the switch to that side to get it out from under the remaining spike heads and carefully lift it out of place.
The removed switch can be attached to cardboard for storage or moved to a new location for re-installment. I often make S hooks of wire or brass strip that I slip over the top of the backdrop and then hang the switches near their intended use area.
I often build switches on the workbench, then "un-lay" them for use at a later date. I have found that particularly helpful to keep the layout functioning during construction and expansion. On my layouts I have generally been starting from the south end and working north. I install flex track and commercial switches for the main track and sidings on a temporary basis between the end of the handlaid track and the north end staging. I will build up a supply of pre-made switches while I'm running the railroad. I will lay ties and some tracks off the main track while I operate the rest. When I get ready to make the next big leap, I can pull up the affected flextrack and commercial switches, lay ties in that area, then install the preassembled switches and connecting rails on the main and sidings and be back in business in a a couple weeks. I have also used this strategy at a couple clubs. I could build switches at home then bring them to the layout on meeting nights. That accelerated my production since I found I could install pre-assembled switches much more quickly than building them in place.