Thats Crazy. if this is your only bath, you do what you have to do to prep tub for removal while in use ( remove tile and greenboard, any flooring etc...)
tub is still capable of being used if you hang visqueen on studs. Then next day remove toilet if within close proximity, shut off water and remove drain/spout any clips on backside and yank out whole or in pieces, prep for new tub. Third day install new tub, reverse order. New greenboard and tile can follow fourth day. (All considering everything goes as planned no studs rotted no relocation of fixtures.) Two weeks your not a Pro!