If you have never opened up a laptop for repairs, I would not suggest starting with a panel replacement
Disassembling a laptop can be tricky and you need to have the service manual that describes the process, or risk damaging the laptop.
As far as panel compatibility is concerned, you will have to research that, although the safest bet is to replace with the exact same panel (same part number). Only the manufacturer knows what other options maybe exist.
Also, lcd panels can be really expensive when buying induvidually through Ebay, so if you have no relevant experience, it's best (and proably cheaper) to give it to a professional.
but i'm living in a country that ... well i guess you all know how middle east is . i'm soon leaving to states but i wish i could do something before i leave . you mean i cant just replace my UHD panel with FHD or HD one that has the same pins and size ???
"i cant just replace my UHD panel with FHD or HD one that has the same pins and size ???"
Not always. Laptops are not as standardized as desktops. On a desktop, if you - let's say - have an HDMI port then every monitor with HDMI will work. Laptops have an internal port called LVDS, but apart from that there are other plugs for power supply and the monitor inverter that are not standard. I have done lcd panel replacements, but always with the same exact part number, even if other part numbers mention compatibility with the same laptop series. You might have the same laptop with a different motherboard revision that needs a different lcd panel.
As I said, if you have no experience in that, you risk spending money for a panel you will not be able to use. If you decide to go for it after all, then at minimum find the service manual so you know how to disassemble the laptop, take out the panel and order the same exact part number.
my UHD panel is fine but i hate it because its locked on 48Hz and lenovo has no fix for it thats why i want to replace it with FHD . i dont need to replace my current UHD with another UHD panel . ok what can i do now ? or maybe there's nothing i can do