I did use texdroider_dpi from the play store but got stuck with a boot loop.
Since i didn t have recovery on my new phone, i had to hard reset it using hardware button combinaison.
Then I got another problem, no keyboard !
I had to launch the browser and use vocal command to search google for android keyboard apk.
Once setup, i managed to log on my account.
The thing that I don t understand is that the DPI is now changed to 320 (the value i entered in texdroider_dpi)
It is just fine but I thought that hard reset would remove this change.
Anyway, phone is working great now. Here are just information if someone has the same bootloop problem.