Need help removing paint without ruining the bluing underneath

I need help to remove the paint on the Berthier 1890 rifle but I want to do it in a way that doesn’t ruin the bluing underneath. I have no Idea why it was painted in the first place but I would like to get it back in working order. As well as having paint everywhere on the metal it also has paint in the barrel. Any help and or suggestions would be greatly appreciated. Gun in question is circled in red. Side by side comparison with the longer version of the Berthier. The paint is also likely lead based.