Here are my recommendations for the refocusing process after you get the glue off:
Don't try to focus with video. That may get you in the ballpark, but won't get you critically sharp.
Here's what worked best for me:
Choose a scene outside which has objects that are about 5 feet away, 20 feet away and infinity, all in the same view.
Choose subjects that have a lot of texture such as brick walls, roofing on houses, concrete etc.
Best to have bright sunlight coming from the side to enhance texture, Don't shoot in late evening where high ISO noise will affect image.
Shoot in natural mode. Do not use gorgeous mode. it is over sharpened.
Place the H on a stable surface, no need to fly it.
If your lens is focusing too close, you will need to turn it clockwise.You will probably not have to move it more than 1/8"
Place a pencil mark on the lens mount and a series of marks 1/32" apart on the lens barrel adjacent to it.
Take a series of still shots using jpeg mode
Adjust the lens one mark between shots
Compare the shots side by side at full resolution zoomed in at 100%. Faststone viewer is great for this.
Find the image that is sharpest at 20 feet and acceptably sharp at 5 feet and infinity.
Set the lens to the mark that corresponds to that image,
Shoot another series with the lens set just before and just after this mark to see if they are sharper.
Take some shots at 1 foot away as well. if your lens is razor sharp at 1 foot, it is still focused too close.
Before cementing the lens, take some test flights and shoot stills and video which include subjects close and far out to infinity.
Do a search for Mickeyboo. He did an excellent video on what to do. Understand that success or failure may depend on when your camera was made. Early cameras had the lens threaded into the lens mount while later cameras employ a mount without threads. With those the lens simply slides in or out and it's possible to position the lens where it ends up canted in the mount.