Car is not taking gas,,is it fuel filter ,and how do i know if it is on 2003 BMW 325i

Car does not want to take gas, and moves slow up hill

Asked by for the 2003 BMW 325i
Pull the filter and blow through it, you can tell pretty quick if there's any restriction. If it hasn't been changed for a while, it's probably a good idea to change it anyway.
Is'nt quiet a deal to get to the filter,I am told it's installed inside the fuel tank and the tank is a completely fixed and cannot be opened and entire unit must be replaced to replace filter..I find that very odd that a filter can cause so much to replace.please let me know if this is correct because it is an expensive maintenance
It's not in the tank, usually at rear RH side close to fuel tank.