I just got an LMT 10.5 and need to install a KAC rail.

I have the pin puches, etc, and I have done this about 5 times before. For some reason, these pins seem stuck more.

How can I be sure of what direction to hit them out, and is there some trick to moving them?

Preparation is usually the key. To be on the safe side, thoroughly soak the two taper pins with Kroil overnight. When the time comes to drive them out, fully support the front sight base. You want the taper pins to absorb all the impact. Brownells sells an AR-15 front sight bench block (part #080-000-252) for $34.97 if you want to spend the money. Wood will work as a support, but if you have a friend's help, your best bet is to put a 4MM socket under the taper pin. It'll support the front sight base, and when you drive the pin out, it'll go down into the socket. Use a 3/32" nail set (found at Lowe's etc.) and a hammer around 16 ounces or so. Give them a couple of good, hard whacks (you don't want to pussyfoot around or you'll just mushroom the pins.) You'll want to drive them out from left to right (the same direction that your takedown pins pull out.) Once they are broke loose, use a 1/8" pin punch to tap them completely out.

I will order that bench block.

Also, how do you get the front sight off without scraping up the barrel?

Putting grease on the barrel helps keep scratches to a minimum.

The LMT uppers I worked on had straight pins, not taper so you should be able to drive them out either way.

Once the pins are out spray the FSB area and barrel down with CLP. Then spin the FSB around on the barrel a few times to break any burrs. Then slide it off the barrel.

Quoted: Then spin the FSB around on the barrel a few times to break any burrs.

Sounds smart. These are the little tricks that I would not know unless someone told me.