Originally Posted by gecho

The bottom bracket is a cup and cone type. Removing the 15mm pedal bolts alone won't be enough to remove the pedals, a crank extractor is needed to push the pedal arms off the square tape spindle ends.

You could replace all the individual parts that make it up with a sealed cartridge bb as they are fairly inexpensive.

This video shows how to do that.
https://www.youtube.com/watch?v=1BrVjDFqotE