I have sent mine in, latest status from GI bill is that they have received it and are reviewing it for approval. Basically all you have to do is register with the GI bill to get your eligibility approved - this means filling out a form on the website and then they take about 2 weeks to verify that you paid in and haven't used up all your funding. They you submit a single form with a copy of all your testing reciepts/results/checkride completion or rating and it is supposed to take about 1-2 months to get the money back

If you need more details or are still having difficulty you can PM me.