These units are now repaired/supported by Duncan Aviation. To remove the EX500/600, you will need: Avionics standard 3/32 allen wrench. FSD, ATD150, MHD300, EX500 and EX600 product lines, D98-00001-58B, 1/2 3 ATI Duncan Technical Support •Normal Business Hours Ph: 800-562-6377 (Int’l 402-475-2611/ Avionics Repair…