To install the mainspring only grip removal is nesassary..
To install the rebound spring the sideplate will need to be removed..
After removeing screws with propper paralell ground bits..
Hold the revolver sideplate up with thumb from left hand just resting on top of the sideplate..
With a rubber or wood screwdriver or mallet, non marring, Strike the grip frame were the the right grip would be, right in front of the grip indexing pin, several small strikes should loosten the sideplate.
Some fit pretty tight but NEVER pry on the sideplate as this will warp it.. Some take several good strikes, the vibration & inertia is what removes them..
Congrats on the 610 BTW..
Gary/Hk