Step 1, have you any qulifications or have you done any training in these subjects?
Step 2, have you approached you employer. If so and they say that there is no training budget then ask them that if you train youself will they give you some work in the area?
Step 3, have you applied for any of those many jobs advertised that sat: - "Sys admin reuired, must have unix blah, blah, also required java etc but not essential as trining will be provided?
Step 4, try doing some work for yourself in your own time, you might take it along to a prospective employer to show as an example of your capabilities.
Step 5, network try and establish contacts with people working in these technologies, let them know you are interested. Most jobs are not advertised they go to people in the know.