As you have to update the JVM you need to user the SUM tool to update the java now.
download the sum tool from service market place.
Uncar the tool.
Then run the tool . Select the system details. In the tools it will ask you to select the xml file or directory for the patch you want to update. please use directory option. Place the JVM update file in the directory.
Please also check if JVM is read by JSPM in your system if read you can update it using JSPM tool also.
Please refer to the below note.
If your system is of Netweaver 6.4 please follow the below Note where the JVM update is cleary mentioned alongwith the steps .
If you are using Netweaver 7.* then please follow the below Note .
If you want to know the prerequisits , please follow the below Note
Bharath Kumar Reddy.M
JVM generallay depend on JAVA release
SAP JVM 4.x - NW 6.40, NW 7.0x
SAP JVM 5.x - PI/CE 7.1x
SAP JVM 6.x - PI/CE 7.2x and NW 7.3x
You can use JVM switch tool or SUM tool or more preferably do manual upgrade so that you are aware that what changes you have made.
If you are upgrading only JVM patch level then there is not need of memory parameter changes, So just download new patch, extract and replace files by previous JVM. Restart system once done.
If you want to crosscheck whether it reflects or not read java dispacher logs. There in first few lines you will get to know what is patch level of JVM and path of JVM.
if you are already using SAP JVM 4.1 you do not need switch tool, because this tool is only to move from partner JVM to SAP JVM one.
To apply the latest patch of SAP JVM 4.1, take a loo at the following relevant notes:
1884813 - SAP JVM 4.1 Patch Collection 33 (build 4.1.033)
1133020 - How to import a SAP JVM patch into an AS Java
1442124 - How to download a SAP JVM patch from the SMP