Ideally you should use a “thermal conductive glue”. You can search online for it. For me this was a non-critical fix so I just used a small amount of fabric glue which will stay flexible so I can take it off again next time, if there is a next time.

Alternatively unstick the sensor from the drive, and leave it connected to the cable.

Removal of these screws can wait until the entire bracket assembly is out of the chassis. Remove the screws when you remove the bracket from the drive, step 23.