Lightbulb how to change external memory to internal

this is my vold.fstab1

## Vold 2.0 fstab for cardhu

#######################
## Regular device mount
##
## Format: dev_mount <label> <mount_point> <part> <sysfs_path1...>
## label - Label for the volume
## mount_point - Where the volume will be mounted
## part - Partition # (1 based), or 'auto' for first usable partition.
## <sysfs_path> - List of sysfs paths to source devices
######################

# Mounts the first usable partition of the specified device
dev_mount sdcard /storage/ext_sd auto /devices/platform/msm_sdcc.3/mmc_host
dev_mount usb /storage/usb auto /devices/platform/msm_hsusb_host


how change the line to: sd_external = internal memory?