Lynx Enduro 400 F Owner's Manual page 171

Some models
Open drive pulley with special tool included in tool box.
Screw tool in the threaded hole and tighten to open the pulley. Remove belt.
1. Tighten to open pulley
All models
Open the driven pulley by twisting and pushing the sliding half. Hold in fully open position.
WARNING!
Never rotate the drive/driven pulleys when emergency cut-out switch is at OFF position.
1. Tighten to open pulley
46 OPERATOR'S GUIDE