Hello everyone. This is my first post so take it easy on me.

I recently bought a Firenze GL5000 at a rummage in decent shape as a fixer upper as I am not sure how much I want to spend on a good bike until I know how much I will use it.

I was looking at replacing the cranks which are the older cottered type. I am assuming to replace the cranks I would most likely need to replace the BB as well.

So my question is, Can I convert it over to a new modern style bottom bracket? and if so how would I find out what size I would need?

Thanks in advance for any help. I am totally new to biking.

Rob