The trans must come out. I'd say it's simple but hard work. Definitely doable yourself as I had no help. You'll need a transmission jack with a strap and make sure it can tilt in all directions as getting the trans back in is the hardest part.
Take a look at the shop manual here to see what the job entails. Full shop manual
http://sluggyjunx.com/auto/2014_Fiesta/Service Manual.htm
If you're looking for someone who can do the job for you at a reasonable price and who knows these cars hit up Francisco Olivares on FB. He's South East Houston but I think he might do mobile work too if you got the space