What is the simple step by step way to install Opa on Ubuntu

Please,

I hate to install what I do not absolutely need. I do not want to install Vagrant. The instruction on opalang.org is not complete as wget http://download.opalang.org/ubuntu/opa_1.0.X%2BbuildXXXX_XXXX.deb did not give a clue about the build. I am using 32-bit ubuntu.

Thanks.