Husqvarna Rider 115C Operator's Manual page 22

Make sure the lifting lever comes above the cutting deck grip.
3 Push the cutting deck in and make sure the guide bolts fit
into the grooves on the deck frame, one on each side.
4 Fit the cutting deck's pipe together with the deck frame's
pipe.
5 Grip the front edge of the deck and slide it in.
6 Push the deck until you feel the pipes touch bottom.
7 Open the catch forwards.
22 –
English
Maintenance
8 Fit the cutting deck lock.
9 Fit the belt according to the picture.
10 Tension the belt with the belt adjuster.
11 Fit the front cover.
12 Set the cutting deck height control in any of the positions
1-5.