Nepenthes roots aren’t what I would call fragile, but they definitely aren’t thick and robust, either. Be gentle, but remember that you’re trying to get rid of the old soil, so pick off old chunks even when it clings to your roots.
Do everyone a favor, and don’t attempt to photograph the procedure with one hand while shimmying with the other… using both hands makes this a lot easier.
I start by tipping the plant to one side over the soil-catching bucket with my hand firmly at the base of the plant, where the stem meets topsoil. I use this contact as a brace as I shimmy the pot to free the soil.
Weeds. So. Many. Weeds.
If the Nepenthes is root-bound, there are tons of weeds (as there are here), or the soil has compacted, the soil will come out as one solid clump. If not, you may get loose soil. Loose soil can be messy, so just hover over your bucket.
Brush soil free from the Nepenthes roots, and separate out any weed roots. Now, rinse those roots! Go ahead and pour some of your distilled water over them to loosen up and carry away remaining soil.
Super! Now you’re ready to re-pot your Nepenthes into the fresh soil mixture.