I will be sighting in my RRA 20 inch upper tomorrow.
Any suggestions about a common household tool for
adjusting the front sight post?

It looks like a pair of needle nose pliers would work to
twist it however I have been accused of being "king kong"
with small parts like this and have a history of breakage,
stripped threads, etc... and would like some suggestions
before I try any adjustment.

Any comments are appreciated.

I use an unfired round...the tip of the bullet works quite nicely.

yep bullet tip would be fine



depress the detent with the tip and spin in the direction needed at the same time. that way you cant mess anything up since its copper jacket

Good in theory.  More diffult in practice.  I am reduced to using small forcepts to help down the detent, and larget forcept to rotate the post.  Not ideal.  There is a tool for this purpse.  Suggest we both  need to buy it.

You can use a bullet tip on the plunger, and a very small screwdriver on the sight post itself.  I just did this tonight putting one back together,  once I got past the stage where I could use my fingers.

The needle nose pliers will work, I've done that too.  

Oh, and remember, Front Oppostie, Rear Same

(although it's easy on an AR, since the FSB is marked...takes all the fun out of it!)