The union declaration of the registers offers access to register bits and bit fields without affecting the rest of the register.
/* using a hex value */
T0CON0bits.T0OUTPS = 0x7; /* Select 1:10 postscaler */
/* using a binary value */
T0CON0bits.T0OUTPS = 0b0111; /* Select 1:10 postscaler */
This is the recommended way of updating bit field register configurations, which is simpler than the alternative options.