Safety is most important. If by yourself, you mean at home, but your wife or someone can be in the area to check on you, you might be fine. I certainly suggest making sure someone knows where you are and what you are doing for safety reasons as there can be some sharp edges and awkward handling of the parts.
As far as the cage only, its just bolts and time. Usually making sure the area around the cage is clean and free of easily burned chaff etc. is a good idea so you can use an angle grinder with a cutting disk on it. The heads of the T bolts, especially when worn, are not wrench friendly. Simply grinding them off is usually the best way to go about removal.
If your 40 is similar to my 80 where the cone mates to the tin work above the conveyor augers, you will see a couple strip shims fall out when you remove the cone. Make sure you re-install them when you put the cone back in. Often, when installing a new cone, the installer will find the new cone does not fit the same as the old one that took a set shape in the machine. They often figure those shims were for making up a gap from manufacturing tolerance. They are not. They are required to be there for engineering design and assemby of the multiple pieces of tin that connect to the cone.
I strongly suggest using all new T bolts and nuts.
What surprises might come up? That is an individual machine call. Once the rotor is out, it will be easy to make a list of parts that are hidden from view and get them on order before you start removal of the cage.
I dont have any pics that are of any actual help with cage removal and install, because that is difficult to show in pictures. But I do have these few of my 1680 with the cage removed so you can see how the cage is fastened to the structure. On the right side of the machine, (passenger side) you can see a couple of brackets that support the cage in the grate area. Getting the nuts on the bolts and tightening them will be likely your greatest challenge of the install. A ratcheting box end wrench and a lot of patients will certainly help.
Here I have the drivers side half removed.
Everything removed. Dont mid the concave hanger. That is my own creation and of no consequence regarding the cage change out.
Here you can see the two stand alone brackets and rear support where the hardware install will be your worst enemy.
And just for reference, a pic looking forward from the back of the machine.
I hope that helps a bit.
Just for giggles and some further reference, here is a link to a picture thread of what I did when installing the new parts. Inside this linked thread, is a link to a previous picture thread that has pictures of the bent cage parts and components.
Link to the thread with pictures.