1. download either Harpo's txt binner gui or Dekhranic's SoaSE Mod Tool GUI (I use the latter)
2. convert the 'GameInfo' folder to TXT from BIN (you'll want it to put the new files into a new folder directory; NEVER OVERWRITE the normal files)
3. create a mod folder. In Vista, you'll put it in- C:\Users\AppData\Local\Ironclad Games\Sins of a Solar Empire\Mods-Entrenchment v1.03\[your mod name here]
4. open up the entity files in Notepad or WordPad. I use NotePad. Now, simply change the following line (the brackets are for clarity purposes)-
{planetUpgradeSlotCount 18.000000} to whatever you want. This line happens to be from a superweapon. You can also change what type of slot it takes up by changing the line {planetUpgradeSlotType "Tactical"} to "Civilian" for a logistics structure. I currently am unsure what the slot type for Mines is.
5. the X10 mod is to my knowledge not compatible with Entrenchment 1.03. Also, are you trying to merge the mods, or stack them? The difference is that merging is when you actually merge the folders of the two mods together; stacking is when you enable the mods together/sequentially.