You shouldn't have to remove it, as Pat points out.

I found it easier to install with the protection plate removed.
Also, if you get the two white plastic snap-on covers for
the new model Marshall 290 regulator, you can then snap on the
larger one with the part that protects the drain vent just as
you make the last 1/4 turn.  That part of the plastic won't
clear 360 degrees because of the tank.  Having the protection
plate off helps.

My RV shop had recommended cutting of that part of the cover
away, but my method didn't require it.

Of course, you'll probably sheer the bolts when you remove
the protection plate, so be ready for that with some new ones.

                                Richard A. Jones
                                Boulder, Colorado
                                '81 Vanagon  Mr Bus
                                '87 Syncro Westy  El Jefe