The odds are the speaker will be soldered directly onto the logic board inside your phone so in order to actually replace it, you're going to need some really, high end equipment and tools, along with trained skills to de-solder and re-solder components on an existing logic board. Most smartphone service shops just replace the entire logic board when a particular component fails, it's just not economically viable otherwise. Something like replacing just the speaker would involve costs several times higher than the original purchase price of your phone (that's almost all labor, with the part itself being just a small percentage of the billable hours).
Very few phone models have modular components that can just be swapped in and out, and that's a feature on specialized, higher end phones. Your Jelly is a low-end, budget-class model so it's even more unlikely to have such a feature.