2. install them.
3. use this link to download SP Flash tools. same for zip/rar, extract.
4. try long pressing the power button, the phone should power off after a brief vibration. if not- let the battery drain it will switch off automatically.
5. charge the phone to around 70% at least but do not switch it on or connect it yet.
6. open SP flash tools. select this file
from the extracted rom folder under scatter-loading
7. VERY Important : select 'download only' mode for flashing. if the phone was running and had root access i would recommend backing up your IMEI number, but its out of the question in your case.
8. click on the green download arrow.
9. now connect the phone.
10. you will see a red line filling the bottom of the flash tool window followed by yellow and purple.
11. a dialog saying download complete with a green tick mark will pop up.
12. disconnect the phone.
13. switch it on, do a factory reset via settings if you want.
Hope this works, all the best.