If you look carefully at my gun, you'll notice the red dot mount isn't the correct mount for my red dot. All that mattered to me, is the screw holes lining up. I ordered a cheap mount from Amazon that was for a bushnell for around $30. I filed off the locator studs and mounted my shield.
With the availability of videos on YouTube, I would attempt to do it myself. Worse case, I could take a pile of parts and pay $125 to have it put back together.