Oracle Database Discussions

Hi,

I need a help here and quick one please.

I create tablespace with these setting
CREATE TABLESPACE test
datafile 'c:/test/l_ind_scotia_01.dbf' size 50M autoextend on next 10M maxsize 30000M
extent management local uniform size 4M segment space management auto;

now i want to change the setting of the uniform and make the new statment like that

CREATE TABLESPACE test
datafile 'c:/test/l_ind_scotia_01.dbf' size 500M autoextend on next 10M maxsize 30000M
extent management local uniform size 128M segment space management auto;


so i just want to do 2 things:
1-resize the datafile wish is fine with me : it is done
and then resize the local uniform size from 4M to 128M which i could not do that and i dont know how?

please i need big help here
i read some artical saying, i can not change the local storage setting

:(:(:(
hellllllllllllllllp

Thanks