I have SBEII that I bought with a ComforTech stock and have purchased a Steadygrip stock to use during turkey season. Can someone walk me thru the change out process? I have taken the ComforTech stock off and want to make sure I put the Steadygrip on right. It looks pretty simple, slide it on and then the lock washer and then the lock nut. Just seems like several less parts than with the ComforTech. Also what is the square plate with the center hole and the 2 slots on either side for? maybe a sling? Thanks for any advice. Gearing up to get Tom this weekend.