Can I upgrade the internal components by swapping them out?

Hi there!

I have an iMac (21.5-inch, Mid 2014) with the i5 processor (1.4 GHz Dual-Core Intel Core i5), 8 GB 1600 MHz DDR3, Intel HD Graphics 5000 1536 MB - and I was wondering if it would be possible to upgrade the internal components (eg. CPU, Ram, SSD, etc)?

I know you can upgrade the hard drive to SSD but i also saw a few videos on youtube that upgrades the i5 CPUs to i7. They also upgraded the RAM component by swapping everything out completely.

Would you guys know where I would be able to order these parts? I live in Toronto, Ontario, Canada so we don’t have as much access as people living in the United States.

Thanks in advance! :)

Hudson