Just posting this as a "take care in doing this" post!
I bought the Tesi Switch button replacements....and they are a great add on for my Helix. When I was trying to pull off the plastic button/knob on one of the smallest ones under the LCD panel, the whole post came out. I was barely pulling when it just popped out. Now, it still will go back in and function properly but will just slides out if I pull up on it. The other button/knobs needed more pressure to pull off but the button/knob came off as expected.
I've had my Helix since they first came out in Canada 3 plus years ago and have nothing but good things to say about it. I have no expectations of Line6 to repair this as it's my choice to do the "upgrade".
Just be cautious people!