Relay deals with the real-world complexities of how work ges done. Often you will be asked to do tasks, but will not be able to do them, or think someone else will be better placed to do them.
There are two different ways to approach this, depending on whether you are responsible for making sure the task gets done, even if you cannot personally do it.
If the task is not your responsibility, when you receive the task you can decline it and suggest someone else who may be able to do the work.
However, if you want to accept the task but get someone else to do it, you can accept the task and then create a sub-task which you can then send to someone else. Use the New sub task option from the : menu to create a new Collaboration, which you can then assign to anyone else. The person who originally sent the task won't get any visibility of this (which is what you would expect – as far as they are concerned it is still your task), and you'll be able to create a slightly different request to your assignee if you want to. You could even create multiple tasks, which you can manage and which you can use to feed back to the task that was sent to you. If you receive work from clients but then have to manage inputs from multiple people, this approach can be really useful.