Unless you really know what you want for weight and balance I would not take the grommets off to match them up. Just place the weight on the inside.
You should not have just any kid with a stringer string your matched frames. When stringing a frame it is very common for a frame to come off the stringer either longer or shorter than it was when it went OM. If you match two 27" frames and they come back at different lengths when string they will no longer be matched.
CAP grommets run from the bottom near the throat to top center of the frame. If you start at the top center it will be extremely difficult to put in the longer grommets near the throat at the end. Start at the bottom and work up to the top.
If it were me I would place the lead tape on the inside of the frame and not under the grommets until I found out exactly what I wanted. You can't just take the grommets off move the tape around and put them back on you need to replace them every time.
I have the ability to drive people crazy, not sure if I was born with it or I learned it but I'm damn good at it.