No step by step, but the photos show how i have installed a Magnefine inline filter to my Transmission. The one on the car has done around 60,000k's plus. The filter contains a very strong Magnet and pleated paper filter. I use it to extend my service interval of the Pan filter, which doesn't filter as fine as this one does. Magnefine website and numerous sites show the benefits etc. of using one. Interesting theory about Transmissions are that 50% of crap in the fluid is metal filings. Also most wear of the transmission occurs in the first 20,000k's. A full fluid flush should be done through the hose you cut into by adding a litre, run car for 15 seconds till a litre runs out, then add another. Keep doing until runs clean. Once this is changed out, a transmission should not wear as much, and pan filter don't need to be changed as often. I find it easier to change the Magnefine every 50,000k's and the Pan filter 100,000k's.
1)There are 2 sizes, depending on the year. My car takes a 10mm filter, as my hoses are 10mm. Some models are 8mm. I chose the return hose as this way it filters the fluid once it has run through the cooler etc. and is clean the moment it goes back to the transmission.
2)Once the hose is cut and ready to install, make sure that the filter is running the right way. There is a arrow showing flow etc. Install it how i have in the pics. The ends are barbed, so the hoses will need a decent push to get them on. The filter also comes with clamps which will need to be installed. The extra hose pieces are for if you want to install it onto the steel lines on your transmission or power steering.
I will post some pics once i have opened it to show the wear my trans had which has done 280,000k's.