The YTS-62 is an instrument with fine build quality and playing characteristics, well worth overhauling.  Unless the instrument has been damaged, it's possible for a person with a reasonable amount of mechanical aptitude, the right tools, and *plenty* of patience to do a better job than you'd get from your local garden variety band instrument repair shop.  Not that that's saying much.  But the key is to do your homework beforehand, take the time, and never rationalize something you know isn't right. When you're tempted to do that, it's best to put the job aside until you are in a better frame of mind.  

There's a lot you'll need to study - at the very minimum, selection, installation, and shaping of materials; how to accommodate different functions such as force transmission, silencing, and sliding (often more than one); how to get linkages to work properly; installing pads properly (fully backed by shellac, no air pockets, riding at the proper height and attitude in the keycup); de-leaking pads; proper cleaning and lubricating; and regulation/key timing.  Ernest Ferron's The Saxophone Is My Voice is a tried and true resource.  There are excellent repair articles and videos on MusicMedic.com, Saxgourmet.com, and Stohrermusic.com.  

 If there is key play due to wear, it will require swedging.  If you take on swedging, make sure you've learned enought to do it right - fully fitting the rod and posts without binding, completely round, and with a true face.  If that's more than you want to take on, have a professional repair shop do the overhaul.  New pads on loose keys wil rapidly develop leaks.

It's important to have level pad cups.  MusicMedic.com has an article on the topic.  Tonehole leveling is important if you want to install firm pads that give the action a nice snappy feel and for less maintenance against leaks in the future.  Stohrer's videos on toneholes are excellent.  If you opt not to level the toneholes, the alternative is softer pads and more time spent de-leaking them.  

The MusicMedic.com repair kit is not adequate for an overhaul.   Read up and start making a list of the tools and supplies you think you'll need.  Whatever you end up spending, it's likely to be far less than the cost of a good overhaul at a repair shop.

Actually overhauling your own horn is a terrible idea. It takes years of practice to become good at overhauling a saxophone. It's something you have to do all the time to be good at it. You could spend a lot of money on tools and materials and end up being very unhappy with the results. In other words a complete waste of your time and money. Unfortuantely there are some god-awful repair techs out there. Fortunately there are some excellent repair techs too. The problem is finding a good one. Saxquest does a great job at overhauls and since the YTS-62 is an excellent horn it's well worth the money to have it overhauled correctly, something you will not be able to do yourself. Do yourself a favor and let Saxquest do the overhaul. Saxquest overhauled a Yanagisawa curved soprano for me and they did a wonderful job. There were no leaks, the action of the keys were adjusted just right, and it's a blast to play because of it. Once you have your horn done right you can concentrate on your playing which also takes years of practice and is something you have to do all the time to be good at. Cheers.