I've never taken ours out...
But the basics do apply:
Trun off the propane (VERY important!)
disconnect the propane from the stove, and remove the unit from it's location in the kitchen.
Where the propane lines split, and run to the separate burners: run a pipe cleaner up the one that seems to be giving you the reduced amount of flame.
Blow it out, set the unit back in place, reconnect the propane, turn on the propane, and give ti t a test...
If it's better: bolt the stove back in place.