I'm not sure what the requirements are to convert a bike to a one by setup, this is the bike:
Love the bike but would like to give it the little upgrade.
Any bike can be 1x at the front - just don't change gear and do your normal riding, see how it goes. If you want to proceed then remove the front shifter cable and shifter. Use the limit screws to lock the front derailleur mech into one chainring as a chain guide.
You may choose the big or middle chainring - there's little point in using a grannie chainring in a 1x.
And the best thing is its a reasonably easy revert, should you want to go back to stock.
Basing this answer that the link you posted connects to the correct bike, a KHS 650B 3500 with a Shimano 2x10 drivetrain, PF 92 bottom bracket.
One of the more simple options utilizing few "hacks" would be to replace the current crankset with a 1x Shimano hollowtech II crankset like this Zee model. The specificity of the brand/ model is offered as an example not a recommendation. Your current BB will accept any Shimano Hollowtech II mountain crankset, and my perspective is changing over to a true 1x with a minimum of parts and as few hacks as possible. The 1x Zee will swap directly with your current SLX 2x.
Next concern would be chain retention. You could leave the front derailleur using it as a chainguide by limiting it's cage to the chainline. For a cleaner look and less weight, replace the front mech with a chainguide, removing the left shifter and cabling.
Your current rear derailleur is a Shadow+ which features a chain tensioner that'll be useful for keeping the chain where it should be. Your current 11-36 cassette appears to hit both ends of the derailleur's spec'd tooth capacity though u might be able to use a 40 t cog within your cassette, especially if you select a chainring with a tooth count in the 20's. Appears to be a fairly straight forward task to get the 1x drivetrain you desire.