Setting toilet to tile/concrete slab advice

I've attached a picture of what I'm up against. I've never set a toilet, so that tells you my experience level. However, I have had success with other plumbing tasks associated with finishing a basement. In other words, I like learning.

I've done some research on how to go about setting to the drain in the picture... I believe I want a inside flange, a diamond drill bit for the tile, and attach it using tapcon screws to the concrete slab. I want the top of the flange to set 1/4 inch above the tile. Is this right?

I question using tapcon to anchor--is it enough? I plant to cut the 4" flush with the tile with a dremel cutting wheel. I will then anchor the flange. If the tile is 1/4", the thinset is 1/4", how deep should the anchor go into the concrete? What do most inexperienced people screw up when attempting this?

Thanks in advance for any advice/insight,
Jared

You're in luck. With a 4" waste pipe, you can use a flange that mounts on the inside of the pipe, so basically, just cut the pipe off flush with the floor. The flange needs to be anchored to not only the pipe, but to the floor. That looks like porcelain, which can be tough to drill holes in, but easy with the right tool. Some flanges aren't a nice 90-degree where they fit into the pipe, which means you need a little champher on the pipe. Some are a nice clean 90, so you don't have to worry about it.

Depending on whether it is a wood or slab would depend on what kind of anchors and the size of the holes you need to drill. Use SS screws so if they do get wet, they won't rust. If it is on a slab, then either plastic anchors or lead anchors.