WebSphere 6.1.0.11 (32-bit) to 6.1.0.29 (64-bit) on single server with 2 environments

My configuration: AIX 5.3 64-bit server; 32-bit WebSphere Version 6.1.0.11 and components; LSF 9.0.0.7 with 9.0.0.4 apps; two environments and two WebSphere profiles to equate to the environments.

Ultimately planning to upgrade to LSF 9.0.1.5, and first step is to upgrade WebSphere to 64-bit Version 6.1.0.29. I want to upgrade one environment at a time so on-going development activities can continue on the separate environment. Therefore, I need to install a second WebSphere Application Server to a single AIX server with the two environments. End result would be that I have a 64-bit version of WebSphere for the one environment leaving the other intact and working at 32-bit.

I have installed the 64-bit version using a separate path and created a separate HTTP Server path as well. Having a challenge with the web plug-ins and Lawson-specific servers within WebSphere.

Does anyone have instructions/guidelines/experience with installing WebSphere 6.1 that you would mind sharing? Documentation is somewhat lacking.

I have already installed separate 64-bit versions of MF Server Express, Java and Bouncy Castle.

Does this make sense? I have a shortage of servers and resources that are forcing me to be creative with what we have if at all possible.