I try to DIY basic stuff around my house. I fixed my washer yesterday, and I replaced a rotted baseboard in a bathroom. I have rewired light fixtures, and I've got a passing familiarity with power tools and done hard labor and dirty jobs like removing a wood deck or digging trenches. So I'm not completely helpless, but I am not a 100% confident DIY person either.
I do not attempt to do things that have the potential to kill/seriously injure me, or I can screw up so badly that it will cost hundreds of$ to put right. I don't mind getting dirty, but potentially getting sewage on me is likely not something I'd consider in my wheelhouse either. And that, coupled with the "I've tried to do similar in the past and not been successful" is also going to be in the pay someone else to do it column for me.
I'd pay a professional to fix this type of thing.