I assume you have a manual operated awning. For the best response we need to know who manufactured the awning, there should be a tag or serial number plate somewhere. Then I would suggest you do a Google search for a repair manual online or see if there is a You Tube video on the subject.
2014 Palomino Puma 25RS
2011 F-150 Super Crew XLT
Days camped in 2014 - 23 Camped 2015-47
Camped 2016-71, 2017-33, 2018-29 booked