Rent 12" diamond wet saw half day. Rent 60lb electric hammer half day. Remove broken concrete. Fill with crushed stone base pre"dyed" with dirty engine oil from your last oil change. Tamp. Add oil as needed. Try a qt of atf to soften and swell that seal. Total cost about $400. I once agreed to try to help pull a 4.5 from an sl. Never, ever, again. Little bitty elfin hands put that thing together with demonical torque strength. And loctite. and "special spanner - NPUKEME456(lhthd)".