Usually, no practical user-service method exists for separating a front lens block that was manufactured as a single assembly. In many lenses, retaining parts are glued, bonded, or ultrasonically welded. While it may be physically possible to machine or force them apart, the real problem is reassembly.

Lens elements must go back perfectly centered and aligned relative to each other, the aperture, and the rest of the optical system. Even tiny shifts or tilt can noticeably reduce image quality. Without proper precision tools—and often optical collimation/testing equipment—you may not be able to restore the lens to correct performance.

So the main risk is not just damage during disassembly, but ending up with a decentered or miscollimated lens afterward. If only a single accessible element can be removed and replaced in its original position, success is more likely. But if the whole front group is a bonded assembly, separating it is generally inadvisable unless done by a specialist repair technician.