The filter element won't need replacing Ken unless you've accidentally thrown a handful of soil in your petrol tank!
Opening the filter canister is risky because those who have done it report that it's extremely difficult to reassemble without distorting the rubber seal.
Reviewing your other thread, the suggestion is that you may have "fuel filter syndrome" which means a slight loosening of the two halves of the canister. All that is needed is to grasp it and attempt to tighten. If it moves, you've found the problem. There's a small plastic clip available, originally called the "orange clip" but they're now white. Fitting this prevents movement and so solves the problem. That's what you should check. There's no need to replace anything.
Simon
