Installing springs is pretty simple on our cars. If it's your first time installing them period the first corner will take the longest.
I'd estimate ~20-30min a corner to remove and install the springs, provided no caliper bolts are stubborn, etc things like that.
Read this guide, it's pretty good and I followed it the first time I did my springs.
Installing Mustang Lowering Springs - Mustang Evolution
Unless you have the equipment setup in your garage, I would leave the alignment to the professionals.
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB