modernize, service, pass, overtake, inspection and repair, revamp, revampment, revise, renovation, going over, more...

tune-up, major overhaul, minor overhaul, routine maintenance, complete overhaul, more...

major, complete, thorough, radical, general, drastic, total, comprehensive, massive, extensive, fundamental

drastically change,   change completely,   massive change,   complete makeovers,   more than tweak,   major changes,   complete redo,   drastic changes,   major policy change,   totally change