Firstly, you need to dissasemble the monitor to indentify if the capacitors are indeed the problem.
Then suspect for capacitor issue is bulging, which you can see physically on them, second you can test them via contiunity test with multimeter (it beeps briefly then stops which is better if you have cheapo multimeter or if your multimeter has capacitance which is better).
Second, soldering iron, solder and a tiny bit of a skill.
At last, the replacement caps. They need to be same value and same voltage (or higher voltage, it does not matter if its higher voltage, just needs to be same capacitance, nF, uF, nano farad,mikro farad).
Also you can salvage them from junk stuff, like PSU unit, or old dead motherboard with capacitors, but I think the legs will be shorter than usual.
Idea
View: https://www.youtube.com/watch?v=umsr1suOZ28