SSD Help! - 2011 Macbook Pro

Hi all,

I have a 13" late 2011 Macbook Pro. My uncle upgraded my hard drive recently and I am unsure if he put a "better" HDD or a SDD drive in my machine. I googled the model (HTS725050A7E630) and it comes up with "Travelstar Z7K500" (https://www.hgst.com/products/hard-drives/travelstar-z7k500). Now I recently learned about SDD and I am wondering if it is worth upgrading. I'm simply looking to increase speed and overall performance for everyday use, as it has a few years of service under its belt. I have already upgraded my RAM to 16gb...is it worth putting more money into my machine? and would it be easy enough for a computer amateur like myself to complete the task on my own?

Thanks in advance.