There are bolt holes in the bottom of the pedals. Right towards the middle, you can't miss them. You use M6 bolts in them, I like using ones with hex heads.
Depending on your playseat you may need to drill new holes or fashion a new pedal plate out of wood.
You can also use like a real heavy duty velcro, like 3M Dual lock, if you don't feel like drilling. I dual-locked my T500RS pedals (same thing as yours) to my Fanatec stand and it worked just fine.
I even ratchet strapped them to my old undrilled obutto rig, that worked fine. Zip ties tho, not as much, lol.
