Set SpeedFactor=4 in Options.ini (3 works too but the Magincia-Terfin and Cove-Wrong crossings are barely possible and have to be done exactly right.).  Add toggle_avatar_fast to default.kmp.

Or, if you prefer not to use a cheat you can build bridges as described in "Ocean Travel Without a Boat".

At the teleporters behind the Avatar's house, take the one to the Castle (see the map here).  [Editor's note - you can also bring the First Aid kit, 2-Handed Sword, bow and arrows.  Eldritch got the Wyrmguard armor but you can take a different set, or none.]

If you didn't bring the weapons from Earth you will want the Bladed Staff.  Climb over the mountains behind the hedge maze to get to Yew.  This is the hardest part of the game because you only have 30 hit points.  It's even trickier with the monster patch on in 1.19f.  There's a shack at 23º38"N, 4º36"W.

You need a 2H weapon [or bow] to break the crate to get the key to open the shack and get the Bladed Staff.  If you don't want to bring in the 2H sword then you need to get the Fire Sword and kill a bandit to get his staff - which will break the crate.  [Or there's a Gnarled Staff in the crypt next to the Britain Cathedral].  You can steal a bow in Yew and get the Claymore if you wish.

Now you have to get to Stonegate and enter Britain via the teleporter in the cave.

You need to cleanse Compassion, Honor and Valor. The order is immaterial.

In order to get the Ankh in LB's bedroom you must do the first Terfin visit, have cleansed Compassion and one of the other two. Again the order is immaterial.

You need only get all the sigils. You can completely skip Ambrosia, Hythloth, Despise, Wrong, and the whole Abyss.

You don't need the glyph from Covetous, just the Blackrock crystal ball (kill the Sword Wraith and go to the lich's room using the shortcut on the 2nd level (#8 on the map here).

You don't need the Bell, Book or Candle.