Its a common aftermarket replacement.
Most do this to discard the firewall pulley and cable parts.
You shall have an extra hydraulic fluid reservoir and hydraulic lines to and from.
Check fluid level as a few who do this, just put up with a leak vs doing the work to check or repair the leak.
Its uncommon for the piston to freeze up in the bore, but could happen if water enters the system. In this situation, you'll need to replace the hydraulic puck or the whole release body.
If the clutch is older, the clearance tolerances become wider, and you could experience the same symptoms.
In this case, you'll need to gain access to the mount surfaces and measure your throwout bearing effective plunge depth to airgap. I think its a few .001". But double check me on that.
Good luck.