Most coffee machine manufacturers use a thread locking glue on the PF handle bolts to prevent movement. This glue can be softened with heat which will then allow them to be unscrewed. We recommend pointing a hair dryer for approximately 10 minutes at the section the handle joins the head. A heat gun can also be used to quicken the process. They can then be turned off by hand with a damp towel on the group head or in a vice for better grip if they are stubborn.