In order to remove the lens from the lens assembly twist the entire assembly in order to bend the plastic

Be careful not to break the lens

Peel the lens out of the assembly, it is held in with a soft adhesive

Another slightly different method used by "Bruce" in the comments: to remove the lens from the assembly, gently - very gently - flex the plastic housing with a little pressure on the back side of the lens using a cotton bud (q-tip) until the edge of the lens is exposed, you can then carefully use a fingernail to pry the lens free.

Rotate the housing with your fingernail just under the edge of the lens and it will easily pop free.