I bought a mechanical keyboard about 20 years ago.
It's probably the second or third mechanical keyboard I've bought. (The first keyboard was a nostalgic Aron..)
I used to use this one very well until recently.

Recently, when I press the S key, it gets pressed multiple times... It's like a double-click symptom of a Logitech mouse.
Gemini told me that I need to replace the switch.
However, since this product was made in an era when there was no concept of hot-swap, the switch is soldered.
I remember trying to repair another broken keyboard (Majester Touch Convertible 1st...? Anyway, it's the first wireless mechanical keyboard from Majester Touch) by myself and ruining it. I'm worried if I can desolder it.
I asked a lot of YouTube teachers, but I'm still not sure. Then, I accidentally saw the video below, and according to the comments, the product price seems to exceed the price of most keyboards.
So I looked for similar products on AliExpress, and there are some. There are also super cheap products,
https://ko.aliexpress.com/item/1005008392922210.html
There are products that cost around $20, but if I buy a cheap product and desolder it a few times, will there be no problem... Or should I use a product that costs 2~30,000 won or more...? I need opinions from those who have soldered a lot.
I'm going to use a switch in good condition that I extracted from a broken keyboard.