Failed garbage disposal?

My garbage disposal is dripping from the bottom of the unit. I’m assuming this means a failed seal somewhere and it’s probably junk. I’m gonna pick up a new unit and try the install myself. How hard is it to replace for someone with very basic mechanical knowledge? Secondly, in the meantime, the unit is unplugged and there’s a bucket underneath. Is it possible to still use that sink briefly until I get it replaced or should I stop altogether until it’s done?