I was trying to take out the roll pin on the trigger guard to upgrade to the enhanced guard when the thin aluminum tab broke off in spite of me having a block under it. Can anyone recomend a "expert" I can send it to. Should it be a smith or a welder that does TIG. Before I get razzed for not being more carefull, I have built more than 6 ARs without a hitch. I appreciate any and all advice.