You might as well give it a try first and see if you can do it, and then if it doesn't work take it toa trans shop, i've done prolly 100 shift kits,so i'll give you some pointers,
1. You NEED a inch pound torque wrench, if you don't have one you WILL warp the valve body, also, torque the pan bolts to 100inch pounds and it WONT leak, i have rebuilt many many unites and never had them drip from the pan after i torque them
2. You have to be very very very clean and organized, every valve and check ball and little spring is important, brake cleaner will work fine to clean with.
3. I can't belive you asked that question about the filter, come on,replace the $20 filter, and put the drain plug in also
4. Go get some trans gel, its a sticky blue grease that holds in springs and valve and check balls and then melts down and doesn't effect the trans it all, it is very helpful in reassembly.
5. You dont have to get all the old trans fluid out, and you prolly couldn't if you wanted. You can use the old dex or type f, we put synthetic in everything so there you go.
Have fun and good luck, the most important thing is being clean and organized.