The tub/shower unit seems to be made of acrylic, has no lines and looks like it is only one piece. I would like to replace it with a newer version with higher walls. Is this possible and if so how?

the Tub-to-Shower Conversion Kits can be customized to fit nearly all shower enclosure sizes and conditions much more quickly and affordably than rigid one-piece acrylic or composite-shower pans.