OLD laptop help

[Wheezer]

I got an old Compaq laptop from a friend of mine for helping him remodel a bathroom. It's a Compaq Contura 4/25c. The battery is bad but it will run from the wall plug adaptor. After it checks the memory a key symbol comes up and I am assuming it needs a pass word. It belonged to his ex and so he has no clue what it is, can I remove the battery for the CMOS and reset it so it does not need a pass word? Thanks.