The only trouble I see with this is that removing old cranks takes a special tool. Removing bottom brackets does too, but they can be coaxed off with a little ingenuity.

If this is an operation you are only going to do once, think about taking both bikes to a LBS and have them remove the pieces. Or, if it costs the same to buy the tool, as it does to have the LBS do it, then go ahead and get the tool.

The other tool you will need is the right sized socket to reach inside the crank arm and remove a bolt that is in there.

Sounds like a worthwhile swap, if it doesn't cost too much money.