Help !!!!

I’m a new member here
I recently added a new pistol to my collection
E9 .20 co2 benjamin pistol
My problem is I need to replace the valve face seal the one that seals the cartridge to the valve it seems to use the same seal as a 2240 but my problem is the valve seems to be soldered in place similar to the older sheridan rifles does any one know if there is a way to remove the valve to replace the seal easier or do I need to replace the seal while its still in the gun tube? 😥