Buy a new metal receiver. Problem solved.
o_O...that...does not necessarily solve the problem.
If I'm looking at these videos correctly (
for instance), the Socom Gear PWS has no faux bolt at all, and has a reverse sprung dust cover. I'm confused as to what you are trying to do exactly. Soo, this is my take on it...:
You can swap out springs and make the dust cover act conventionally (spring out, not spring back, thus holding open the cover), but it won't lock because there doesn't seem to be a lock built-in to this one like most airsoft M4s on the market. You can get a replacement dust cover that will lock from some retailer (which should work, since most just grab onto the top of the ejection port); you'll probably need to message the retailer to confirm the dust cover has the lock included and see whether that would even fit the PWS. You would also have to have the proper tools for pulling out (and reattaching) your RAS because the pin for the dust cover is only accessible with the RAS removed (correct me if I'm wrong). But after getting your dust cover working, you would then need to figure out how to release it with the charging handle. Which can be accomplished by jerry-rigging up a faux bolt piece to nudge the cover out and undo the lock like any other airsoft gun does, causing it to spring out, and be what I'm assuming what you what it to be.
Rip off RAS, put a new dust cover on, put RAS back on, expose gearbox/charging handle, figure out some sort of way to latch a normal faux bolt onto your charging handle, reassemble, and there ya go. Not a lot of stuff to do really, just an inconvenient dose of making things work together.