Here's the deal ....
1. Take of the top.
2. Grab a fan and reach in thru the side panel with it holding it up against the top and lining the holes in the fan with the slots in the top panel. One set is for 120mm fans (inner) and the other (outer) is for 140s.
3. Take a screw in other hand ... from the top, outside the case and feed it thru the slot into one of the fan frame mounting holes.
4. Rinse and repeat for the other 3 holes but remember not to tighten any screws 'all the way till all fans are installed.
NOTE: You may have to let gpo of earth grade earth science and that hot air rises stuff.... of course it does but with so little oomph behind it, when against a fan it's irrelevant. The reality is intake fans will be restricted by inlet air filters which can cost you up to a third of your air flow ... if the fan specs say 70 cfm, once any fan is installed, it will often deliver only 50% of that ... Fan specs are a lie; when you see 70 cfm @ 1.2 SP, that means it will produce 0 cfm at 1.2 Sp and 70 cfm at 0 SP... you are lucky if you see 35 cfm @ 0.60 SP... inlet filters can reduce air flow by as much as a third depending on how dirty you let them get. Also don't fall into the trap that the number on in and outs need be close.
So a good rule of thumb is 2 exhaust fans for every 3 intake (filtered) fans. Im guessing here as site just says 10 ... so I will assume 3 front, 2 bottom, 4 top and 1 rear.
(3) front intakes and (2) bottom intakes and (1) rear works very well, that turns the top into a "forced air" vent where air will be pushed out
(3) front intakes and (2) bottom intakes and (1) rear and (4) top exhausts is a terrible idea. Let's do the math ...
For the folks who let dust build up on filters, (5) exhausts x 1.5o wants a safe 7.5 intakes, you don't have it.
For the folks who clean filters regularly, (5) exhausts x 1.33 wants a safe 6.67 intakes, you don't have it.
So here's what's gonna happen .... because of the air inlet restriction decreasing the air flow from inlet filters and the exhaust fans having no such restriction, you will have a negative pressure situation. I'm not worried about the dust that will get sucked in thru the giant rear case grille. I'm worried about the air that carries in . The reason Im worried is that the air that carries it in will be pre-heated by the hot exhaust fro the 750 watt PSU and that 225 watt GFX card.
We use a $35 "garage band fog machine" from Amazon to show his whenever someone says "that can't be". So just use common sense, make sure ya have more insies than outsies so you
don't suck air in. from the back to make up for the difference... and if you're using rads, remember, rad fans always blow in....
https://www.corsair.com/corsairmedia/sys_master/productcontent/49-000175_rev_AB_H100i_QSG_web.pdf
Page 3, Window 1 read the part about "For best performance, mount fans as air intakes into your PC: