For an Eclipse (we just had a thread about this same thing for a betta, but it was a Penguin in question) I think the only thing is to use the sponge method Menagerie suggested. You can't really replace the filter itself, as it is integral. Once the tank is established the flow should slow down considerably, with the bacteria and whatnot that will collect on the inside of the tube and in the filter box, Biowheel, etc. For me, I have never had an Eclipse that had near enough current!
As a precaution--run the plants along some nylons/stockings (if you have some handy). If the nylons run or rip, so will the betta's fins. Many members recommend silk plants only in betta tanks.