'Slip-ins' at my daughters house averaged about 1 hour each. Remove molding carefully to re-install, remove lower sash, chop out parting strip, remove top sash. Test-fit the new unit; remove, caulk outer stop molding & sill; set new unit; chk level/plumb; set top trim piece; caulk inside; re-install molding. Carry two sashes to back of truck for disposal.
2-1/2 Saturdays...done.
Reno:
I understand your logic on leaving a clean job!
