How to make builds from old leagues work again in Standard?

Hi, I've last played PoE in Harvest and Heist leagues, so about 2.5 years ago. Now I found out that a friend is also interested in PoE and we want to try to play together. He is playing in Standard league, which is ok in so far as my Chars have been moved there.
However, I noted that their skill trees are broken, probably due to all the updates in between. I have one char from each league with a rather high level:
- Glamdring_the_thief: I tried to follow this build guide https://www.pathofexile.com/forum/view-thread/2581551 rather successfully, but the guide says that this build does not work anymore.
- Glamdring_the_righteous: I don't even know which build I followed there.

However, now for both chars the skill trees are broken as in some parts are disconnected and I have some skill points left over.

How can I salvage these chars to easily play again? Maybe not at the power level they were before, but preferably without having to find completely new gear for them?

If you just followed a guide and the guide says the build is no longer usable the best thing is probably to use the full reset you are given to reset your tree completely and use the char for another build. Try looking for some 3.21 guides or builds from POE Ninja using the same class and/or skill and use the chars for that. You'll have to change the gear as well though.

You can also try to keep using the build after adjusting the tree yourself but if you just followed the guide blindly and the guide says the build is no longer usable then chances are high you'll end up with a flawed build that doesn't work.

/edit looked through the guide, the skill essence drain is still usable and viable, however the entire defense setup which was based on dodge no longer works as it did before so you'll have to come up with something else here.

Yeah sadly the transition to standard isn't great with all the changes. Personally I would prefer it if a character would migrate to standard with the old tree and you could choose to update the tree but aren't forced to. Similar to divining a legacy unique. At least then you could play your old builds without major overhauls. Now my standard characters are essentially useless as many of them are not easy fixes.

Chances are if they are that old that there is not really a way to save them without at least some gearing changes and even then you might not hit all the build specs you want or need to. There have been some pretty major overhauls since Heist that I don't think you can ignore. Your best bet is to go to the build section under the ascendancy you have and look around to see what comes closest and rebuild.

Thanks for your replies, will have to delve deeper into the topic in this case