[HECnet] VAXStation 4000/90A power supply fan

Good morning ... Subject mostly says it all. One of the fans in my VS4K 90A is noisy. I'd like to replace it. (actually both) Two questions arise: How the **** do I get the fans out of the power supply? I've got the power supply out (that's easy), mostly apart (that's not so easy) but do not seem to see any screws on the fans. Would it be safe to run it with just one (quiet) fan? Any pointers or links would be appreciated. Thanks, Fred ---- Lets call it for what it is - "legacy" is a term that people use in a polite but derogatory manner to imply that the future direction they prefer is not that which they view as the current direction.