The first thing to do is take out the two innermost layers of mesh. There is a huge difference is made in that alone.
If your brave, you can try to remove the little grill on the capsule. I didn't as it's too risky.
Some have changed the shape of the brass metal ring around the capsule to further reduce reflections. Some have also added a little foam to the bottom of the capsule chamber to still further reduce reflections ( I haven't tried either of these yet, so I can't speak to any difference).
Replace C3, C4, and C13 with better caps (subtle differences).
for C3 & C4 try a Xicon Polystyrene film cap .001uF rated for 50v (Found mine at Mouser)
for C13 try a Panasonic Metal Film cap .22uF rated for 50v (found mine at DigiKey)
To reduce body resonances, band the body below the mesh with thick rubber bands to get rid of a little ringiness. Like the ones that band broccoli together at the grocery store.
Outside a capsule change and massive circuit over hauls, that's pretty much the best I know you can do.
It's well worth the time. The mic is, dare I say, really good after the mods. especially for the price.
Good luck