Change one Letter

Gym------Gyp

gyp......guy

Guy = Gun........

Gun=Gin:party::party:

Gin = Bin..........:)

Bin-----Nip

nip.........tip

Tip = Sip....

Sip---------Spy

spy = sky

Sky = Ask.....

Ask----------Ski

Ski........................Kit

Kit = Wit.........

wit= hehehe, you know what i want to put but lets go with
wit = sit