Uncircumsized and dry jelq

How do I do a dry jelq technique when I’m uncircumsized? I don’t wand to hyperextend the skin like the one posted not a long ago on the failure of the skin regrowth.

Also is the gain really permanent? I read it on some (non-affiliated to PE products) site.

Like in the video here.

The gains are permanent after a cementing routine. For more information, do a search.

How hard do I have to squeeze it? Should there be some amount of pain present afterwards or minutes (hours) past it? Like in fast and spontaneous masturbation?

No, you should feel some soreness, like the kind of soreness you feel after a good workout in the gym, but pain is bad. Squeeze with moderate tightness.