I have samsung galaxy sm g900 java
 

Always i get error : There is not enough space


my phones is samsung galaxy clone sm g900

please how can i hard reset o flash

You can hard reset your phone, it will automatically clear the phone storage.
First method:

1) Turn on your cell phone.
2) Now goto Settings -> User and Backup -> Factory Data Reset.
3) Confirm all information on your screen.
4) Done!

Second method:

1) First you should power off your device.
2) Next press and hold Volume Up + Home button + Power button until you see logo of your phone.
3) Then from the menu choose option "wipe data / factory reset" using Volume buttons to scroll options, and Power button to confirm operation.
4) Now select "Yes -- delete all user data", and confirm that.
5) After that press Power button to accept option "reboot system now".
6) Success!

Third method:

1) Switch on device.
2) Dial or press number to call: *2767*3855#
3) That number code will force format on device.


WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.