First off, you need your alchemy and enchanting at level 100. And you'll need 5/5 enchanting and alchemy.
Craft a full set of armor for fortify alchemy. I believe each armor piece should increase it by 40%, I may be wrong. Before you craft the potion of restoration you want to make sure you take off everything from your favorites list and put your set of fortify alchemy armor set onto your favorites list so it'll be much quicker to take on and off
#1. Craft the potion of fortify restoration.
#2. Drink the potion of fortify restoration.
#3. Go to your favorites list and take off all pieces of your fortify alchemy armor set and immediately put them all back on.
#4 Rinse and repeat steps 1 through 3
You can probably do this up to four times before you need to start making the potions you're going to keep. The reason why is because the potions of fortify restoration's effects stack. So the moment you start doing the glitch you only have 30 seconds. Once you go through the steps about 6-7 times then you make the potions you're going to keep.
When you think the percentage is high enough just make like 10 or 12 or however many potions you want to make. And the percentage should be like in the millions or billions.
The way the other guy has you doing it it'll take forever for you to get it into the millions. Because he has you only taking off one armor piece. Once you do it the 5th or 6th time the percentage will start to drop off because the first potion of restorations effect will end.
The way this glitch works is whenever you drink the fortify restoration potion and you take off an armor piece and put it back on, it's going to fortify the percentage on that armor piece. So for example on the first potion the fortify alchemy percentage on your armor piece is going to go from 20% to something like 150% or something around there. So when you take off all pieces of the armor set and put them back on, all the percentages are going to go up.