I know this part is not an easy task but here are few methods to upgrade package on linux embedded device.
1) Method:
Download glibc-2.19 debian package on to device (either directly using curl or download onto PC and scp to the device)
(download the debian package based on your architecture type 32/64 bit)
Use Opkg module to install the new glibc package,
opkg -f /etc/opkg.conf -d ram update
opkg -f /etc/opkg.conf -d ram install <package-name>
Note:
a) verify the opkg configuration file
b) below is sample of config file
src/gz repo <package-repository-url>
dest ram /tmp
lists_dir ext /var/opkg-lists
option overlay_root /overlay
arch all 100
arch armv7l 200
arch armel 300
2) Method:
If you have internet on beagle bone then refer below links and you can find some command format examples.
http://wiki.openwrt.org/doc/techref/opkg
http://wiki.blue-panel.com/index.php/OPKG_%28en%29
3) Method:
Download the package source files on to your linux PC and cross-compile to beagle bone.
And then scp all required files of the package(binary,config files.....)