“Boil and Pop” refers to the act of immersing a plastic figure in boiling water. After about 45 seconds, the softer PVC plastics (usually used in heads and limbs) will soften enough that they can then be “popped” out with a good strong tug. Just to be safe, I use an old pot that won’t be used to cook food.
I only recommend this is as a last resort. Boiling an entire figure can weaken plastic in the long run. Also, unless you plan to paint the whole thing, boiling can discolor some plastics and factory paints.
			


 Easy: A simple parts swap. Little if any paint.
 Basic: Some modified parts. Mostly a new paint job.
 Moderate: New and modified parts.
 Skilled: Lots of new and modified parts. “Frankensteining” often involved.
 Advanced: All of the above, plus a great deal of original sculpting.