Guild Wars 2

Hey guys.
wonder if anyone can help me. . . just want to know if there is a way to unequip my guild heavy armour from its original armour piece

Unfortunately not unless you use a transmute stone and re-transmute the previous skin onto it from another piece like the former one. However, doing that, will cause you to lose the guild armor skin in the process (and thus waste the 1g you spent to get it).