Thanks to pemic for sharing his original design :)
Since I wanted to reuse the hotend mount screws to hold the fan mount, I did a little remix of his file.
On the way I thougt it would also be nice to have the Tevo Logo in the fan cover :)
You will be able to screw the fan holder to the hotend by using the stock screws, I additionally secured them on with a little blue loctite, so they won't come loose over time.
To mount the hotend fan you can use 3mm screws, I even used a "tap and die" to cut the 3mm thread into the mount, but it should work without cutting a thread, too.
I happened to have the exact same screws that Tevo used for the hotend mount and they fit perfectly for mounting the hotend fan and the fan cover.
To mount the radial part cooling fan you can use the stock screws as well, the 2 longer ones on the bottom and one of the shorter ones on the top, but here you might need some kind of spacer, since the screw will now push against the hotend fan and cannot be screwed in completely.
So you can either use a spacer (I happened to have a nut that fits perfectly, you could also use a scrap piece of bowden tube) or cut down the screw in length, but I wanted to avoid that in case I want to go back to stock configuration again.
Pemic had two versions in his original design for the part cooling holder, I also made 2, one being slightly higher than the other (which I need to use on my Tornado)
Depending on the part cooling duct you use and if you use the original print bed, you might run into problems when homing, since the part is exactly on top of the screw head of the print bed, so watchout for that.
Update: I might be adding an additional screw option on the lower end of the hotend fan holder, similar to the original design, that screws inbetween the hotend cooling ribs, it might not be necessary, but I have just bent accidentially the uper two lashes the fan is no longer flush to the hotend ribs and the part cooling duct is touching the print bed on one end :(
Update 02-Jan-2018: I added a beefed up version of the hotend fan mount, so it won't bend that easy anymore. If anyone encounters problems even with the beefed up one, please let me know. Also check the last picture, by twisting the both fan cables two times around each other I avoid the part cooling fan cable to be too close to the x-axis, where it could wear out over time.