The Ultimaker 2+ is a single extruder 3D printer. Without changing the PLA spool and PVA spool continuously during the print you practically cannot make water soluble supports on the Ultimaker 2+ which can be done on the Ultimaker 3. Note that PVA (from experience) is strange material to print, the filament is very hygroscopic and will form bubbles during printing when moist. Also, PVA is prone to clog the nozzle (it cooks easily) it therefore has its own printer core (nozzle assembly) on the Ultimaker 3 (still it clogs easily). Furthermore, it takes a while to dissolve in water.
If you have a single extruder and nozzle, your best option is to use the same material for support, but modify the support settings as such that it can be easily removed. E.g. on thin layer heights (0.1 mm) I usually increase the gap between support and product over the default value, see this answer.
On dual extruder printers, e.g. on the Ultimaker 3 and S5, my colleagues have better experience using Ultimaker Breakaway filament rather than using PVA. As with the PLA supports, you need to "break them away" from the actual product; I use a Leatherman Charge or FREE P4 as these tools have fine pointed pliers. Note that there are removal tools available that are best described as soldering irons that can aid in the removal of support structures:

Note that I have mixed feelings about this product; it is hard to neatly remove supports using these small soldering irons, but it sometimes works.