Rixo yes he basicaly did what the article that was linked was telling you to do... he probably took the gun apart(you NEED the proper tools and a spring compressor!!!!) cleaned and deburred the insides then replaced the seal and maybe the spring and the relubed and put it back together.... with the correct tools and time even ok job at this will usualy make a large difference and if done at or near a pro level will make an amazing diff.... there are plenty of tuners out there you can send it to if you have the money and they will do an amazing job!!! we have a couple good ones right here on this forum!!!
I am not saying dont do it yourself.... I am just saying dont do it till you can really understand that article and have built a good spring compressor to do the job!!!!!!
hell put where you live in your profile there is a good chance someone who knows what they are doing might live close enough they would be willing to help you out!!! its a win/win LOL get to hang out with another airgunner and get to learn alittle something while your at it

Edit: looks like your out around long beach in cali.... I know there are quiet a few good airgunners out there in cali.... dunno how close they are to ya though LOL