how to ugrading to php 7.1

Thanks for your quick response… I followed these guidelines when I installed the mydoli extension: https://docs.google.com/presentation/d/1UQyYJGRVcDOVOahOmenRrvS760XGYDIdqa0KEFDcPmM/edit#slide=id.g232d598c3d_0_80

From the app I have access to the server but it´s not loading customer and invoice data…

here is the system information:
Betriebsystemname Microsoft Windows Server 2012 Standard
Version 6.2.9200 Build 9200
Weitere Betriebsystembeschreibung Nicht verfügbar
Betriebsystemhersteller Microsoft Corporation
Systemname WINSERVER
Systemhersteller QEMU
Systemmodell Standard PC (i440FX + PIIX, 1996)
Systemtyp x64-basierter PC
System-SKU

I´m using dolibarr Version 10.0.2 (latest) with php 5.5.12

Thanks in advance for further assistance,

Semih