So, long story short, I'm wondering if anyone has any insight or advice as to what might be involved switching my focus from Software to Physics in order to eventually apply to a Masters program. I'm assuming I'm going to have to take some additional classes in order to meet prerequisite requirements and prepare for the Physics GRE, but I have no idea what classes I might need to take. On the upside, my Engineering degree involved a lot of math (off the top of my head the only Math I think I'm lacking is Differential Equations), but unfortunately I only took Physics 1 and 2 and nothing more advanced.
It may not be easy, but it may be doable. Most programs want to see a good, solid undergraduate preparation in math and physics to be prepared for upper level physics classes. However, I do know several people have switched from engineering (usually electrical) to graduate physics including myself. I'm also 29 but just finished my first year of graduate school in physics. I worked in industry as an electrical engineer for a few years but realized that industry and engineering were not very satisfying. I wanted a challenge, and found it, graduate physics has turned out to be an excellent choice for me.
But without more physics classes, getting in may be difficult. Schools may view your work experience as a plus, but you'll probably have to score well on the Physics GRE to show your capabilities and knowledge in basic physics. Fortunately, it is a test that is easy to study for. If you take the time and discipline to study hard, and do well with standardized test taking strategy, you can do well. It will probably do you a lot of good to try and get some more physics and math classes in over this next year. Could you take evening courses somewhere? I'd definitely recommend differential equations, and as many physics classes as you can get. Different schools may list specific background expectations on their program websites.
I basically had a physics minor along with my physics major, and the courses that I had have been a big help on the Physics GRE and so far in graduate school. The only classes I was really missing were a quantum mechanics course (although we got a little of that in a modern physics course) and a class in mechanics. Although I considered taking an undergraduate level mechanics course, I decided to jump right into the graduate class and it worked out fine. I had some catching up to do, but I really enjoyed the course.
So if you decide to go for it, good luck, shop around for programs, get some more classes if you can, and study hard for the Physics GRE.