how to remove paint on lower unit?

[matt167]

My '64 650 lower unit had what I thought was a scratch but it does catch on a fingernail, does not weep oil or anything like that, but I want to remove the paint around it to see if it is a crack or not as the lower did have a bit of water in it so freeze crack would have been a possibility tho it was very low on water/fluid when I drained it... What is the best/ safest way to remove the paint?