The chair I sit and edit the videos upon, had seen better days. In this video I will remove the warn out seat and replace it.

0:05 I am removing all the bolts, nut and machine screws holding the seat and back rest to the base of this swivel chair.
01:28 When in doubt use an angle grinder and a hammer.
01:50 The new seat is somewhat retro and green, but comfortable.
02:11 I unscrew the seat from its legs and mark the corresponding holes from the base of the original swivel chair.
02:55 I initially used insert rivets, which are squeezed into place using a specialist riveting gun.
03:46 Thick rubber is cut and drilled, before placing between the base and seat.
04:27 I bolt the two ends together, but the inserts didn’t hold in place. They work far better on sheet metal where it can pinch more firmly.
04:55 Reverted back to wood inserts which are screwed into place using a beefy allen key,
05:37 When I am happy with the hold, I unbolt the base and screw the original frame with backrest and arms.
06:40 This is pretty comfortable but the legs are in the way.
06:46 I use an angle grinder to make some kerfing cuts onto a scrap pipe to test the bend. It was a little too sharp, so I tried a hack saw which was much nicer.
07:20 Moving onto the chairs legs, the metal was much thicker and I should have make more kerfs.
07:46 I decided to cut all the leg shorter and cap them with some rubber feet.
08:17 The seat is complete.