Not hard to do if you know how. But then you can say that about lots of things.
1- Take the grips off
2- Remove the 3 screws holding the side plate on
3- Hold the cylinder latch to the rear slightly
4- Tap the grip frame gently with the handle of the screwdriver, the sideplate will lift itself off
5- Compress the mainspring, unhook from the hammer stirrup, remove
6- Install the new spring into the frame, hook tip onto hammer stirrup
7- Make sure the hand is pressed in and fits within the hand window
8- Replace the sideplate gently, press it into place. DO NOT hit it or force it!! Make sure the latch piece fits over the latch pin and the hand stays in place
9- Replace the screws. If everything is in the right places, test the action. If it works, replace the grips. If not, remove the sideplate and get the hand and latch in place and try again.
Once you've done a few dozen, they're easy!! Just like brain surgery!
If all this is intimidating, consult a pro (good luck finding anyone who works on old Colts anymore).
