Not just for smart watches either
You will need a spring bar tool to do this, but if you shop around for a new strap you can usually find some that come with the tool and new spring bars
You will also need to know the size of the strap before you buy it, measured in mm.
Set your area up before you start, a towel is a good idea as it stops things rolling and it also protects you watch from hard surfaces (you will notice that I was in too much a hurry to get my new bracelet on my watch to follow my own advice!)
Working from the back, remove the old strap.
Wiggle the pronged end of your spring bar tool in between the strap and the watch lug. The spring bar has a ridge that the tool will grab
Gently apply press inwards towards the strap and away from the watch to depress the spring bar. At the same time, apply some downward pressure so the bar will pop out.
Pressing too hard and/or fast, and the tool may slip damaging the watch or the strap
Now attach your new strap/bracelet
Make sure the pin bar is central positioned in the at either end of the new strap or link bracelet
Again working from the back insert one end of the spring bar into the hole in the lug
Then using the spring bar tool, depress the other end of the pin bar allowing it to slide into the lug.
Repeat on other side
Encourage the pin bar into the hole and make sure both sides are secure (you don't want it to fall off)
These photos were taken just over a month ago and since then I have upgraded from the 360 to a Huawei. It's worth noting that the Huawei has easy pin bars, they have a small little posts that you can move (and therefore release the pin bar) with a fingernail, thus removing the need of a fiddly spring bar tool
Just so you know I am no expert just a normal bloke finding things out for himself and trying to share so if you like this or think you know someone who might like it then please share it
And if you like to buy me a coffee, I have no objections !
paypal.me/bowmore