I have read about people thinking taking down the Ruger .22 handguns can be challenging and I came across this link and thought maybe this could be helpful if you are having trouble 
http://www.hornetproducts.com/ViewProduct.asp?ModelNumber=MK-TDI
Hope that helps
Josh
http://www.hornetproducts.com/ViewProduct.asp?ModelNumber=MK-TDI
Hope that helps
Josh