if possible and available, install a newer JVM version locally and then point the startup configuration of the servers to this local jvm copy outside of the wM installation.
Check setenv.bat, setenv.sh and/or wrapper.conf or custom_wrapper.conf files where jvm path might be specified.
Make sure to use the same major version (java 7 or java 8) which is already being used by your installation when not using official SAG JVM patches.
When using newer JVM major version (i.e. java 8 instead of java 7) without patching the installations accordingly with official SAG patches this might corrupt the whole installation.
For all wM releases prior to 10.x the standard support has ended meanwhile and for accessing latest fixes you will require an Extended Maintenance agreement for these releases. Without that you will only see latest published fixes before standard support ended.