Hi everyone, I am in the process of changing out my barrel. I am watching the video by IWI on how to remove barrel and following the steps. I am now stuck.

I took the hitch pin out and I placed a sling swivel inside the mount. I am now trying to get the mushroom nut off but it wont turn by hand. It won't budge.

What can I use to get that to turn?

This is the video I am using to do the barrel swap.

IWI Tavor SAR barrel removel.

Thanks everyone for the help.

thin allen wrench?

I tried a thin allen wrench but no go.  Below is what I was finally able to do. I posted this on another sight that I asked the question on. An all bullpup sight.

I was finally able to get it off. Man the video said it was hand tight . . . NOT!!! I asked on Facebook and someone in email that I have talked to from the board here. Everyone has been of great help. I couldn't find the right tool but found the right tool for the job. I used to do stained glass years ago and one of the pliers that I used to break the glass with worked perfect. It didn't mar up the washer at all. Once I got that off it took me some time going step by step to get the rifle tore down and then back together. It is now the rifle that I wanted. I love the 16.5" barrel. The 18" is fine but I love the 16.5".

Quick question....are you checking the  head space of the original bolt with the new barrel or did you buy a barrel and bolt kit that is already head spaced?

I bought a barrel from someone. The headspace issue is fine. IWI from my understanding used to sell just the barrels (this is how I got mine from an individual who had bought just a barrel). I will have my gunsmith check the head space when I have the flash hider tighten. I don't have the tool for that. It dropped in just like the original barrel. The bolt assembly dropped in just like it had with the 18" barrel. No issues yet and I don't see having any either. I think its just something IWI started doing.