When looking at your bits in edit mode under the "Contents" tab, you should see something that looks like this:
PsiCorp Particle Script v4.0 PsiCorp Penis Control Script v4.0 PsiCorp Penis Position Script v4.0 PsiCorp Penis Sculpt Script v4.0 PsiCorp Penis Texture Script v4.0 Settings
What you generally want is the position script. The procedure is simple. Open your inventory and drag the position script into it, thus making a copy. Then, simply drag it right back into the contents tab, which then should look like this:
PsiCorp Particle Script v4.0 PsiCorp Penis Control Script v4.0 PsiCorp Penis Position Script v4.0 PsiCorp Penis Position Script v4.0 1 PsiCorp Penis Sculpt Script v4.0 PsiCorp Penis Texture Script v4.0 Settings
This means the first step went right, and theres only one more thing to do, namely make sure this new script is empty and thus has all 10 slots available. For this, simply enter this into chat:
This will clear out the script you just put in, and you now have more space for your modifications. This process may be repated for a total of 10 scripts (the first one, and trailing numbers 1 to 9), which allows you to control a total of 100 prims per penis, which should accommodate the largest mods quite comfortably.
If you instead need space in the texture or sculpt script to handle a particularly large texture/sculpt notecard, simply copy the texture or sculpt handler, and use either of the following, whichever applies:
/5 cleartex /5 clearsculpt