collimation knob broken-advice

[graham.hobart]

Hi all, on my 8" Newt one of the collimation plastic knobs knurled end has come off the screw thread, so the actual screw is still in the scope but hard to get at. Apart from re-aralditing the knob back on - any other suggestions.
Not keen on drilling it out just yet!
Graham

[Den]

You can get a (left turning direction) screw remover from local tool shop.
Or maybe heat up end of screw driver push it in creating a screw slot let it cool and then screw out.