i did disassemble two lenses for the the same raison, but never a Helios 44.
For me it was quite simple : the core (with the glass element) was rotating inside a cylinder. Some small piece of metal was blocking the lense at the end of the run (infinity mark.).
All i had to do was to remove the small piece of metal.
So i could "unscrew" (by the same mouvement i screwed a screw
) the core of the cylinder.
then you just have to rotate the core from 1/4 or 1/3 of turn, then rescrew it into the cylinder.
the piece of metal should block the core when it arrive at the infinity mark on the barrel (before puting those piece of metal, the core can go further than infinity.)
it was quite easy and fast (10-15 minutes)