how can chanage my router 4G to 3G

[AbduBasit]

i want change my router 4G to 3G
MANUFACTURE - HUAWEI
MODEL - E5172As-22

 

[Phillip Corcoran]

There is no need to change your existing router, it already supports 3G:

Huawei E5172As-22
4G LTE-FDD 800/900/1800/2100/2600MHz
4G LTE-TDD 2600Mhz
3G HSDPA/HSUPA/UMTS/WCDMA 900/2100Mhz.
2G GSM/GPRS/EDGE 850/900/1800/1900MHz.