This thing is stuck. Any pointers on getting this thing to budge?

Dynamite & chainsaw.

When they don't come out I've had to drill them out carefully as to not damage the brass housing. You can drill out the metal in the middle and then start to pull pieces out

You can also make your own puller that's more sturdy by drilling out the middle metal thing and tapping it out for a bigger bolt and then using that bolt to create a puller to pull it out

Might have to cut the front off somehow. The Google videos are BS. This thing will not budge. Thank you for the input.

Patience. I usually have to soak in vinegar and/or wd40 and let sit for a bit. Then I use large channel locks to start wiggling and gently pulling. It'll come out eventually.

They do make a puller but it's expensive.

Do yourself a favor and use some silicone when installing the new one.

Fortunately I've never had to deal with a filter cartridge. However, I have fought and won the battle vs an O2 sensor on a 6 year old vehicle using Liquid Wrench. A little patience is key as you gotta let it sit at least overnight.

Think I'm screwed now. Soaked it in CLR and it broke trying to remove. It's really hard to grab now.

update?

It came out. In many pieces. I hate it.

Experience - what you get when you don't get what you wanted!

The first time I changed a cartridge had to chip tile away because the tile guys were idiots. My first fear was obviously busting tile that I then how to figure out how to fix.

Next came getting the cartridge out. The rubber seals on the cartridge peeled away, so as I pulled the space between the cartridge and the ?mount? became even narrower.

Next with a death grip on my pliers, feet against the tub in a position like I was about to heave a squat rack.

The final act was to avoid flying through the tub and wall when the cartridge finally popped out.

A couple of months later I had to replace one in another bath. Terrified I held off for several days until my wife became a bigger fear. That one took 5 minutes at most from start to finish because it all just worked like it is supposed to work