It's only hard to do if the holes don't line up when you're trying to assemble the parts, and this is common with the company that makes Kioti's BH. The tolerances are not great and there will generally be "something" that doesn't line up.
Assuming the install is equal to the CK20 with that BH, the loader frame can be installed already, the BH brackets install on the bottom of the loader brackets up front and to the draw bar replacement as Virgil said. I don't understand why he said assemble the cross member before the loader as the BH brackets hang down in front off the loader bracket, and the draw bar mount at the back has nothing to do with the loader. Those two brackets are all the additions of hardware you'll make. Once you have all the parts assembled on the BH and the brackets on the tractor, you'll need to install the hydro connections at the valve block's (that runs the loader) power beyond. The hoses connect from inside the BH controls, run up into the subframe and out the front end to connect to that valve block.
Now if it's different than the CK20, I'm sure it's similar.
If you've never done it, and are mechanically inclined, you should be able to do it, however, I recommend you have it installed as there will invariably be some parts missing from the company that makes the BH for Kioti.
Generally most members have posted that it's less expensive to buy the BH at the time you buy the tractor. It seems most deals are made by giving breaks on the attachments, and if you're getting 0% or reduced financing, it won't make so much difference to the bottom line that it would be a great problem.
You may consider asking about getting a Woods Backhoe instead if you decide to install it yourself. Their tolerances seem to be much better and the parts are always there (accroding to a couple of Woods/Kioti sellers). John