Background:
I recently began a high end build, where I went with a Mega billet upper and lower, a Noveske barrel and BCG and a Seekins LPK and NOXs rail.  The lower assembled nicely.  While assembling the upper, I screwed up the order and didn't put on the barrel nut first, having no prior experience with a pinned block/barrel and non-low profile gas blocks.  I asked Noveske how to remove the pin, as it was mushrooming after installing and then attempting removal.  They were awesome and sent me instructional pictures and told me not to damage it, just send it back to them and they would fix the issue free of charge.  (FYI their blocks fit on barrel crazy tight regardless of pin).  I sent it back to Noveske, they removed the pin/block, slid my barrel nut on and pinned the gas block back on.  Fast forward to me nearing completion, I try installing the Seekins 12" NOXs handguard and notice it doesn't mate completely against the upper.  Then I notice the handguard bolts don't match up with their corresponding holes also by just about 1/8".  The anti-rotation tabs on the back of the rail do not slide over the Mega upper, which apparently is an older known problem now that I researched it.  Basically I'd have to go through the whole process of removing the Noveske gas block again to swap out rails, since the barrel nut is already installed behind it.  I've read of people hammering them on with a nylon hammer, but with this combination I don't see that working.  

Main Point:
I'm looking to remove just shy of 1/8" off the ears on the 6061-T6 aluminum Seekins NOXs rail.  What would the best tools and methods be for doing this one would find in a well provisioned home mostly wood shop?  I have a dremel, bench grinder, router w/ milling bit or hand files.

Just use some fine files. Using a dremel might fuck it up, and files are nice and slow and you can check your progression.

Hand file. No need to overthink it.

Aluminum works quick, won't take you long at all. Touch up with alumiblack

I would steer clear of anything powered. Especially a dremmel.