I repainted mine last year. The paint was flaking off massively. I
used a wirew brush attachement to an angle grinder. It worked
reasonably fast, but the wire brush does disintegrate over time so you
need to wear goggles and might need more than one. Then I primed it
with two coats of Rustoleum primer then painted it with 2-3 coats of
Rustoleum Gloss paint. I used a paint brush. It came out great.