There is nothing wrong with the stitches already on the awning so there is no reason to remove them.
How to repair awning fabric.
Do not remove the stitches.
Follow the instructions below to reinforce the stitches on the fabric awning so that it will last a long time.
Fabric awning repair can take on many forms from repairing holes and rips to replacing the entire mechanism of the awning.
Insert the new awning into the channels on the roller tube and slide it all the way down to install it.
Roll the fabric up and reattach the legs before you put the awning back onto the rv.
Unroll the spring with a vise grip slide the spring out of the roller tube and roll the old fabric off of it.
This is how i do it as a single person two or more people would be a different procedure and is the procedure seen in many othe.
Unlace the awning far enough that you can lift up the corner.
There are two options depending on your budget.
The absolute best option is made by eternabond.
Follow the same procedure as for rips in the fabric body cutting your repair fabric long enough and wide enough to extend beyond the rip.
This is strong enough to patch roofs on rvs or campers and does marvelous on awnings for all fabric types.
The longer answer is that you need to get quality repair tape for awnings and apply it properly.