I can't find much information about upgrading an IBM Aptiva in the 90s, the whole computer that is. I know the aptiva was mainly (or exclusively?) sold as a package with monitor.

So, let's say you bought a pentium 1 aptiva in c. 94 and wanted to upgrade to pentium 2 in 98. Was there an option to buy just the computer since you already have the peripherals, or could you trade in or how did it work?