Gearbox oil changes

I checked the oil in the overdrive, main and transfer boxes today (the things you do on a day off from work!). Overdrive and main just needed a top up, but the transfer box, though ‘full’ was so black I decided to do a full change.

No real dramas to report, now I’ve realised the best way to undo the inspection nuts is to use a metal bar to increase leverage....

The one thing that’s not ideal, is how I end up with loads of oil on the garage floor. Any way of avoiding this?! I always laugh at the way you can only know if the ‘box has enough oil is if it dribbled out of the hole down your arm!

Annoying, I have overdrive on mine too and find the oil moves between boxes , ie it gets pumped towards OD which gets over full, i commandeered the turkey roasting dish bit enough to catch the spurts and the volume
Sometimes I put a big plastic sheet down too

I've had plenty of gear oil in what's left of my hair as well as all over the drive. Having plenty of rags available helps, sheets , and a drive I don't care about.
I had very black oil from the main box last year, and some "bits" and then soon after a new / refurbished gearbox. Earlier this year I went wading too deep by mistake and had water in just about everything so it was quite milky looking then...

I use a pump bottle with a bent over tube, I poke my finger in the hole while I pump and feel for the oil coming up to level. This also means I can keep my finger there while I reach for the filler. Not perfect and I smell like the cats peed on me, but not much on the floor.