Assuming that the flange and thread on the cylinder are in good condition, put it in dry with the new fibre washer. No sealant, you don't need it. Then it can come out easily enough.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local