sony protector error

upon power-up, my sony str-d1015 receiver goes into protect mode. i
checked all speaker connections and all checked out ok. i followed the
advice of another member who had the same problem and found part #
stk350-230 to be at fault. i purchased IC stk350-230 from mcm and want
to install it but, i can't see how to release the old part. it seems
to have a
plastic hold-down (or shield) around it holding it in place. can
anyone help me? thanks. jim