This is a fix for the step 4 out of 7 crash when launching Minecraft. You know the one where you're launching for the first time and it's got to go through a set up phase, and gets to the 4/7 marker where it installs the mod and just freezes. Yeah, this is your fix. You can find videos on youtube about "installing 64-bit java" and stuff, so if you're more of a visual learner check those out.
The problem lies within Java 32-bit setting a cap on your usable ram, and to fix this you'll need Java 64-bit. So here we go!
Part 1. 64-bit Java
Step 1) First you'll want to find out what Operating System you have. 64 bit Java will ONLY work on a 64 bit OS. So to find out, use your control panel and guide yourself to the "System" page. Look for "System type:" and see what it says. If it says 64-bit Operating System, you're in luck.
Step 2) Now you need to acquire the 64-bit Java. To do so, you'll have to install it manually at http://www.java.com/en/download/manual.jsp Look under windows for "Windows Offline (64-bit)" this is your golden goose. Install it, and uninstall old Java versions from your computer.
Part 2. Allocating Ram
Step 1)First you will need to open minecraft and go to edit profile. From the "Profile Editor" tab look for the very bottom "JVM Arguments" and click the box. This will allow you to select and change the contents of said box. The very far left line should (it did for me anyway) look like "-Xmx1G". You can see that 1G means 1G ram. MOAR WE SAY. So change the 1 to a 2.
Step 2) If you're using just Pixelmon, setting it to 2G is properly enough to get you past the hurdle and onto playing the game. But what if you got more mods installed? While technically you can probably still go higher to 3G and possibly 4G. I do not know what side effects this will have on your system. Most mods are pretty small compared to Pixelmon, so 2G should be good enough. So system safety warning lol
So now that you both A) Got Java 64-bit, and B) allocated yourself some more ram. (Leave that box clicked by the way. Unclicking it causes it to go back to default i do believe. Well did for me, but yeah just leave JVM clicked on.) You should be good to go!