No pushing it with the brake off.
If the pedal is higher than usual then you have a belt failure / pulley failure.
So it will be a case of removing the deck then getting underneath
I block off the fuel cap using some cling wrap, remove the battery then stand the mower up vertical on it's rear wheels.
This gives clean access to the belt & the clutch pulleys.
Even better all of the crud under there will drop to the floor rather than in your face.