If you're happy to give it a go it isn't really that hard, but it might not work and will take half a day anyway.
You need to have an identical rim, otherwise the spokes will be the right length.
The only tool you need is a spoke key.
Get the rim and tape it quite loosely next to the old one, making sure it has the same number of spoke holes and if the spokes are offset (slightly left & right pointing) get them aligned. Best to keep the valve holes together.
Remove the tyre and rim tape and swap the spokes over one at a time, keeping all the overlaps the same. The reason you need to tape it loosely is because the last few spokes can be awkward to fit.
Do each nipple up loosely at first then get on with trueing it.
You don't need a jig, turn the bike upside down and use a felt tip or chalk blu-tac'd to the frame/fork to get the alignment.
Tighten up the spokes bit by bit till its fairly true. First get it round, then get it true, then get it dished right, then get it tensioned. That's the right order.
You will need a rim tape, and lots of courage when you ride it first time, when it will go ping ping ping, but that's normal.