A method of assembling wall panels includes mounting a plurality of PVC fastening extrusions to a wall in a predetermined parallel, spaced apart relationship, each having a length much greater than a length of a wall panel and having two spaced apart resilient bent end securing walls extending from a base, each securing wall having a projection, each wall panel having a main wall panel and four bent end sections with recesses and corner openings, pressing a bent end section into the spacing between the securing walls to cause deformation and snapping back thereof a projection engages in a respective recess, sliding said wall panel along the parallel, spaced apart fastening extrusions to a desired position with the corner openings permitting said sliding action, and repeating the steps of pressing and sliding for additional wall panels.