A 2.5" Samsung 860 evo SATA 3 SSD can be installed the same way you install a mechanical HDD.
Connect a SATA data cable from the motherboard to the SSD and connect a SATA power cable from the PSU to the SSD.
You might need a bracket t hold the SSD in place or use double sided tape and stick it somewhere in the PC case.
If that's not enough watch video below. Video