Best ways to deload?

You have lots of options. It partly depends too on how much fatigue you've built up, and your goals.

You should probably take at least some days off completely from weights and high intensity cardio. It's a good mental break at least.

If you were doing low reps before, lower the weight. If you were doing high reps, lower the reps and/or lower the weight. Maybe lower the sets too.

Personally, I do similar to you with UL so a workout every other day, and my current deload was four full days off. No exercise at all. Then four days with two workouts with reduced volume. The first of those was full body instead of my usual U or L, for usual workout time. I reduced set count to fit in usual time. For some exercises like barbell row, I could only lower the weight so much while still keeping the 45's on, so I did half the reps of normal. For others like dumbbell fly's, I lowered the weight by 20% and lowered the reps to 12 from 15. For db bench I did same 10 reps at about 67% normal weight. Those choices are more about convenience than pulling out the calculator, tbh. The main point is, reduced volume. Next workout will be higher volume, midway to my normal. Then after 8 days, back on regular cycle, almost. Maybe I'll do one set less for the first two workouts, I'll see how I feel.

It's often called a 'deload week', but that's not the same as 'rest week'. In your case, so far that's 4 days rest instead of your usual 2, and if you reduce the intensity in your remaining 2 workouts this week, that's a deload week. Or, take the next couple days off and do a full body workout Saturday, again with reduced intensity as mentioned, to help prepare for your returning to normal on Monday.

This is a good read:

https://powerliftingtechnique.com/deload-week-vs-week-off/

Best way is very nuanced. I literally have done over 100 different ways to deminish stress over the years. The best for you will depend on your goals and training history. I as a powerlifter prefer to program washouts when I'm far from competing and high intensity deloads when within a few months of a comp.
I'm not a big fan of taking days off unless medically necessary or perhaps vacation-travel but in most cases it's not a bad idea when thinking long term. For my clients I default by dropping volume every so slightly, but usually prefer washouts going into new programming as it transfers better for programming and retrieving data for both short and long term.