I'm not going to "give" you a post (don't have one), but we ( the forum ) could "help" you to getting the post correct, and instruct you on modifying it.
#1 ---what version of Mastercam do you have ? and what machine control ?
#2 ---create a 1" circle in mastercam and interpolate the bore with a 5/8" cutter using a 2D contour -tool #1
---spotdrill 2 holes -tool #2
#3 ---post all ( use " TEST-POST" as the NC filename )
#4 ---manually modify the NC program to run correctly on the machine ( save as "TEST-MACHINE" as the filename )
After you have done this
#5 ---create a compressed ZIP folder on your desktop, and copy into it
--the MCX file
--the post you used
--the un-edited NC file from #3
--the edited NC file from #4
#6 ---on your next message, upload that compressed file as an attachment, and then we may know what your next step would be ( use the "paper clip" icon at the top of this box, browse for your ZIP folder, then upload -you may have to wait a little)