It's easy enough if you know what you're doing, have the required little tools and the dexterity. There are several ways in which these links are connected and it's easy to make a mess of it.
I have done (literally) dozens now and find it easy...but you may have difficulty.
I couldn't do it as I am a bit cakhanded, to say the least, but Mr. Sam has done it countless times for our family and me. Maybe you know someone who could ?