You need to have a special filter wrench to do it, which is a cup-type as opposed to a band-type. Filter is cartridge not spin-on.
No. Its a cartridge inside the canister.
can you send a fax without a ink cartridge
When its dirty you need to change the filter.
No need to bleed lines, since the system is under pressure.
As the filter clears the water, microscopic particles attach to the filter. Since these particles slow the flow of the water, the pressure increases. This indicates it's time to clean your filter. Most filters need cleaning 2-3 times a year. If your pressure increases more than 2-3 times a year, it may be time to replace your filters.
Normal pressure is between 14-16 psi. when the filter is clean.
If the problem is on the cartridge (as in your rather vague question) change the cartridge. You need to give more details for a specific answer.
If you have a sand filter and the sand has been in it for more then four years and you are finding that it needs back washing too often or the water is just not cleaning up the way it used to, replace the sand. If you have a cartridge filter the and the back pressure is constantly too high even after cleaning it you may need to deep clean it with a cleaner recommended for your particular type of cartridge (get advice from your pool shop or the manufacturer) or the cartridge may be torn or worn out in which case it will need replacing.
No , if you have a D.E. filter instead of an older cartridge filter than the D.E. can get pretty messy if when you filter clean , and if you have a backwash when you backwash .
If you have a sand filter the sand needs replacing every 3 or four years. If you have a cartridge filter it wont need replacing until it breaks. Cartridge filters can become blocked over time causing the pressure to become to high as a result of the restricted flow of water, this can be fixed by getting an approved (for your filter) cleaner, this will clear the pores in the filter and keep it going so long as the membrane doesn't break.
It depends on the type of filter... different filters are designed differently. You would need to tell us the model or type of filter.