Basically you just need a clamp, a cut out vortex cylinder (about 12mm+ wide), cordless drill and desired drill size for tube.

1. You drill straight down the PVC Cylinder at a 90 degree angle with it clamped in place.
2. Then you rotate the PVC Cylinder at probably 45-60degree angle, and drill down where you drilled the original hole
3. That way you can slide the tube in so it's inline with the PVC cylinder as shown in the diagram above.
This is what I got, I did a dodgy job but I could still fit the tube inline with the cylinder


NOTE: I thought of this basing Davidvaini's Vortex Cap idea using PVC Pipe as my vortex and used the original vortex block idea. I'm not sure but Davidvaini I think told me this is what he did.