Oh boy... I have felt this way too. I think it helps to write down or discuss the thing you are trying to comprehend. If it is really long, I usually leverage CTRL+F to get to the right section. If it is OSHA, I usually scour the interpretations too (especially if I have a question myself).

I know there is a service that does this for corporate clients but I cannot, for the life of me, remember. I will try to find the name tomorrow.

I am on board with you on this. Some of the regulations I have been reading is like deciphering a manual on how to build a circuit board using a piece of rope and cardboard. I have to reread the content multiple times just to try and understand what it is talking about. If you find a better way please share. So far I have been lucky enough to speak with Drew Hinton, he is like the OSHA regulation whisperer.

Print, read, write notes, highlight, reread, discuss.

I'm only familiar with Acts and Regulations in Australia. (eg: https://legislation.nsw.gov.au/view/html/inforce/current/sl-2017-0404)

My usual approach is to review the key 'Parts' and 'clauses' in the Contents window to locate the sections relevant to my current issue.
Bear in mind the 'Definitions' clauses(s) and who has 'duties' in relation to the issue.

I do read them a couple of times, paraphrase them out loud on my own, and then recite them as if I was explaining the concept to my teen kids (sometimes I do this last step as a fact). Only then I give myself credit for a practical understanding. Recently I have been discussing them with a friend as a final step of cross checking my reading comprehension.