Bios Password

I have been given an old 486dx4 pc but someone has put a password on the bios setup.Dont know the password
Dont know what the m board is or if there is a jumper that will reset bios. I have removed the battery for a few hours to no effect How can Iaccess the bios setup and remove the password request
Also the cd rom which is a 4 disc rom recognises cd’s but will not read them. also when trying to load win 98 after f disk and format message appears saying win 98 requires a processor 66mhz andabove processor is 100mhz amd